Abstract: Addressing codes frequently used in optical codedivision multipleaddress (OCDMA) systems are introduced. They are typically one dimensional timespreading code, twodimensional code and three dimensional code. The means and variances of crosscorrelation for these codes were analyzed. Based on the fundamental principle of optical correlation receivers used in incoherent OCDMA systems, with different addressing codes taken into account, the bit error probability (BEP) of the system was studied. The dependence of optimum decision threshold on the basic parameters of addressing codes and the number of simultaneous users was obtained. Finally, numerical simulations are carried out, and the results show that system BEP performance is optimized when appropriate decision threshold is taken.